The practice of staging productions for theater and musical concerts in the same performance facility has necessitated the development of flexible stage layouts. The general purpose approach to the utilization of such facilities has encouraged the use of movable stage backdrop panels. A production team is able to set up any number of stage layouts by simply moving the needed backdrops into position on the stage floor.
Examples of stage panels supported in a generally vertical orientation range from solitary panels supporting scenery to integrated stage backdrop setups enclosing three sides of a stage with multiple panels positioned next to each other to complete the enclosure. Where more than one panel is needed, it is important that adjacent panels be correctly aligned. Each panel edge should be capable of abutting and engaging an adjacent panel edge. This is useful for presenting visually clean lines to the audience, and to ensure proper acoustics.
Individual stage backdrop panels may carry vertical panel components extending thirty to forty feet and may weigh as much as two thousand pounds. The vertical stage panels are carried at the front of a support base. Counter weights are carried at the back of the support base to stabilize the panel. Despite the counterweights, the center of gravity of a vertical stage panel remains well up the length of the panel, and the high center of gravity contributes significantly to the difficulty of safely maneuvering vertical stage panels. Maneuvering this much mass and achieving alignment of upwards of forty vertical feet of panelling has proven a daunting task for stage production companies that must also ensure the safety of the personnel moving the panels into place.
One example of a panel support structure useful in this area is disclosed in U.S. Pat. No. 5,115,608 issued to Abraham et al., on May 26, 1992. The '608 patent discloses a plurality of casters in clusters mounted to the base structure in at least three positions. Each caster cluster is also capable of independent height adjustment, facilitating the leveling and alignment tasks. While a useful system, problems are still encountered. The larger and heavier panel structures continue to be difficult to precisely maneuver in increments small enough to be useful to the stage crews. Considerable time is lost in repetitive alignment attempts to achieve the final fit. An additional unanticipated difficulty is encountered in those theaters where the stage floor, for whatever reason, is no longer hard, flat and smooth. Cracks and low spots can develop in stage floors which trap caster wheels. Sudden tilt, and abrupt accelerations and decelerations of the panel structures can result.
A panel transport method and apparatus that combines ease of maneuverability and safety in the transport of portable, vertical stage panels of all weights and heights over uneven as well as hard, flat stage floor surfaces would be a welcomed improvement over previous transport mechanisms.